Chapter 16 and 17 Campbell Biology Flashcards

7600263595	Transformation	change in genotype and phenotype due to the assimilation of external DNA by a cell; discovered by Griffith	0
7600263596	Bacteriophages	viruses that infect bacteria	1
7600263599	DNA Nucleotide	nitrogenous base, pentose sugar called deoxyribose, and a phosphate group	2
7600263600	Adenine	nucleotide complementary to thymine in DNA	3
7600263601	Guanine	nucleotide complementary to cytosine	4
7600263602	Chargaff's Rules	1) the base composition of DNA varies between species 2) the percentages of A and T bases are roughly equal	5
7600263603	Double helix	shape of a DNA molecule but not of an RNA molecule	6
7600263604	antiparallel	meaning the two sugar-phosphate backbones run in opposite directions (5' to 3' and 3' to 5')	7
7600263605	Purine	adenine and guanine; having 2 organic rings	8
7600263606	Pyrimidine	cytosine and thymine; single ring nitrogenous bases	9
7600263608	Semiconservative model	model for replication in which two strands of the parental molecule separate, and each functions as a template for synthesis of a new, complementary strand; new molecules have one original strand and one new strand	10
7600263609	Origins of replication	short stretches of DNA having a specific sequence of nucleotides; where replication begins	11
7600263610	Replication fork	y-shaped region where the parental strands of DNA are being unwound	12
7600263611	Helicase	enzymes that untwist the double helix at the replication forks	13
7600263612	Single-strand binding proteins	bind to the unpaired DNA strands, keeping them from re-pairing	14
7600263613	Topoisomerase	helps relieve strain from untwisting by breaking, swiveling, and rejoining DNA strands	15
7600263614	Primer	RNA nucleotide chain produced at a DNA strand to begin replication; needed for DNA polymerase to begin adding DNA nucleotides during replication	16
7600263615	Primase	synthesizes primer	17
7600263616	DNA Polymerase	enzyme that catalyzes the synthesis of new DNA by adding nucleotides to a preexisting chain	18
7600263617	Leading strand	receives 1 RNA primer and extends from the primer by a DNA polymerase; continuous replication in the 5' to 3' direction toward the replication fork	19
7600263618	Lagging strand	DNA strand elongating away from the replication fork; requires several primers and produces new DNA in fragments	20
7600263619	Okazaki Fragments	short series of segments on the lagging strand	21
7600263620	DNA ligase	joins the sugar-phosphate backbones of all the Okazaki fragments into a continuous DNA strand	22
7600263622	Nuclease	DNA cutting enzyme	23
7600263623	Nucleotide excision repair	DNA repair system involving nuclease, DNA polymerase, and ligase	24
7600263624	Telomeres	special nucleotide sequence at the ends of eukaryotic chromosomes	25
7600263625	Chromatin	DNA and protein combined	26
7600263626	Transcription	synthesis of RNA using information from DNA	27
7600263627	mRNA	carries genetic message from the DNA to a protein-synthesizing machinery	28
7600263628	Translation	synthesis of a polypeptide using the information in the mRNA; occurs at a ribosome	29
7600263630	Template strand	The side of the DNA that provides a pattern for the sequence of nucleotides in an RNA transcript	30
7600263632	RNA Polymerase	pries the 2 strands of DNA apart and joins together RNA nucleotides complementary to the DNA template strand; enzyme in charge of transcription	31
7600263633	Promoter	sequence on the DNA template where RNA polymerase attaches and initiates transcription	32
7600263634	Terminator	sequence that signals the end of transcription	33
7600263635	Transcription unit	stretch of DNA downstream from the promoter that is transcribed into an RNA molecule	34
7600263637	Transcription factors	collection of proteins that mediate the binding of RNA polymerase and the initiation of transcription in eukaryotes	35
7600263638	Transcription initiation complex	whole complex of transcription factors and RNA polymerase II	36
7600263639	TATA box	a sequence of nucleotides that is part of a eukaryotic promoter	37
7600263640	RNA processing	stage in eukaryotes where both ends of the primary transcript are altered and splicing out of introns and joining of exons occurs	38
7600263641	5' cap	modified form of Guanine nucleotide added onto the 5' end during RNA processing	39
7600263642	poly-A-tail	at the 3' end an enzyme adds 50-250 more adenine nucleotides to the mRNA to form this	40
7600263643	RNA splicing	accomplished by spliceosomes	41
7600263644	introns	intervening sequences; do not code for protein, are removed from the pre-mRNA	42
7600263645	exons	coding sequences of the mRNA; get translated into amino acid sequences	43
7600263646	spliceosome	complex made of proteins and snRNAs; remove introns from pre-mRNA and join together exons	44
7600263647	ribozymes	RNA molecules that function as enzymes	45
7600263648	Alternative RNA splicing	known to give rise to 2 or more different polypeptides depending on which segments are treated as exons during RNA processing	46
7600263649	Domains	discrete structural and functional regions of proteins; usually coded for by different exons	47
7600263650	tRNA	the translator; carries amino acids to their proper position on a mRNA	48
7600263651	anticodon	particular nucleotide triplet on a tRNA that base-pairs to a specific mRNA codon during translation	49
7600263652	Wobble	flexible base pairing at the third nucleotide position of a codon	50
7600263653	rRNAs	make up ribosomes; catalyze reactions during translation	51
7600263654	P site	the site on the large sub-unit of a ribosome that holds tRNA carrying the growing polypeptide chain when the A site is empty	52
7600263655	A site	the site on the large sub-unit of a ribosome that receives the tRNA carrying the next amino acid to be added to a growing polypeptide	53
7600263656	E site	where discharged tRNAs leave the ribosome	54
7600263657	Signal peptide	targets a polypeptide being synthesized to the rough ER	55
7600263658	SRP	recognizes a signal sequence on a polypeptide, connects to it, and then moves the polypeptide and its ribosome to the rough ER	56
7600263659	Polyribosomes	enable a cell to make many copies of a polypeptide; multiple ribosomes translating the same mRNA	57
7600263660	Mutations	responsible for the huge diversity of genes found among organisms; changes in DNA	58
7600263661	Point mutations	changes in a single nucleotide pair of a gene	59
7600263662	nucleotide-pair substitution	replacement of one nucleotide and its partner with another pair	60
7600263663	silent mutation	no observable effect on the phenotype	61
7600263664	missense mutation	if a substitution mutation changes only one amino acid of a protein	62
7600263665	nonsense mutation	changes a codon for an amino acid into a stop codon	63
7600263666	frameshift mutation	whenever the number of nucleotides inserted or deleted is not a multiple of three; can result in extensive missense or nonsense	64
7600622293	histone	proteins that DNA wraps around to form nucleosomes of chromatin;	65
7600622294	DNA polymerase I	removes the primer during replication and replaces it with DNA nucleotides on the lagging strand	66
7600641298	Meselson and Stahl	their experiment supported the semi-conservative model of replication	67
7600645542	nucleosome	a core of 8 histone proteins with DNA wrapped around it; beads on a string	68
7600663304	pyrimidine nitrogenous bases	thymine, cytosine, uracil	69
7600671032	telomerase	enzyme found in germ cells and tumors that maintains the length of telomeres	70
7600682798	heterochromatin	highly condensed chromatin	71
7600685554	euchromatin	chromatin that is not condensed and is available for transcription	72
7600695776	one gene-one enzyme hypothesis	proposed by Beadle and Tatum as a result of their experiments with nutritional mutants of Neurospora	73
7600707495	one gene-one polypeptide or RNA molecule	an improvement on Beadle and Tatum's hypothesis	74
7600723905	gene expression	consists of transcription and translation	75
7600734881	coupled transcription and translation	gene expression in prokaryotes; transcription and translation both happen at the same time in the cytoplasm	76
7600758601	uncoupled transcription and translation	gene expression in eukaryotes; transcription occurs in the nucleus and translation happens in the cytoplasm;	77